Question: Express this product in scientific notation: $(1.80\times 10^{-1})\times (9.00\times 10^{-5})$
Solution: Start by collecting like terms together. $= (1.80\times 9.00) \times (10^{-1}\times 10^{-5})$ When multiplying exponents with the same base, add the powers together. $= 16.2 \times 10^{-1\,+\,-5}$ $= 16.2 \times 10^{-6}$ To write the answer correctly in scientific notation, the first number needs to be between $1$ and $10$ . In this case, we need to move the decimal one position to the left without changing the value of our answer. $ $ We can use the fact that $16.2$ is the same as $1.620 \times 10$ $ = {1.620 \times 10} \times 10^{-6} $ $= 1.620\times 10^{-5}$